With increasing usage of mobile phones in our cities, on our campuses, on our roads, in our automobiles and in large congregations of people, the need for reducing the number of blocked calls for a cellular phone system becomes increasingly important. Even with more antennas, smaller cell sizes, and allocation of more frequency bands for cellular traffic, high concentrations of potential users of cellular phones create increased demand for cellular traffic on the existing systems. Allocations of mobile phone frequencies in the 900 MHz, 1900 MHz and higher bands, along with the 800 MHz band provide call capacity. Digital transmission technologies such as TDMA (time division multiple access), CDMA (code division multiple access) and GSM (global system for mobile telecommunications) further increase the call capacity and augment the analog cellular phone system. Digital phones are demanding higher transmission capacities to accommodate a larger number of personal communication services, such as voice mail, e-mail and Internet access.
Even with the proliferation of digital phones, call traffic continues on analog systems. Dual band phones, for example, allow usage of more than one band of frequencies. Dual mode phones convert to analog channels when digital channels are not available or are overloaded, placing high demand on the analog lines.
Demand for services becomes excessively high in specific urban markets, during special events, and during certain emergency situations. A traffic incident on a major freeway, for example, may lead to the need for high priority services for accident victims and emergency personnel, with the possibility of cellular phone calls being blocked while many individuals in backed up traffic chat or do business on their cellular phones.
It would be desirable, therefore, to provide a method for reducing the number of blocked phone calls and increasing cellular phone call capacity.